Should symptomatic iliac screws be electively removed in adult spinal deformity patients fused to the sacrum?

3D CT modeling demonstrates the anatomic feasibility of S1AI screw trajectory for spinopelvic fixation in neuromuscular scoliosis

PURPOSE

In patients with neuromuscular scoliosis undergoing posterior spinal fusion, the S2 alar iliac (S2AI) screw trajectory is a safe and effective method of lumbopelvic fixation but can lead to implant prominence. Here we use 3D CT modeling to demonstrate the anatomic feasibility of the S1 alar iliac screw (S1AI) compared to the S2AI trajectory in patients with neuromuscular scoliosis.

METHODS

This retrospective study used CT scans of 14 patients with spinal deformity to create 3D spinal reconstructions and model the insertional anatomy, max length, screw diameter, and potential for implant prominence between 28 S2AI and 28 S1AI screw trajectories.

RESULTS

Patients had a mean age of 14.42 (range 8-21), coronal cobb angle of 85° (range 54-141), and pelvic obliquity of 28° (range 4-51). The maximum length and diameter of both screw trajectories were similar. S1AI screws were, on average, 6.3 ± 5 mm less prominent than S2AI screws relative to the iliac crests. S2AI screws were feasible in all patients, while in two patients, posterior elements of the lumbar spine would interfere with S1AI screw insertion.

CONCLUSION

In this cohort of patients with neuromuscular scoliosis, we demonstrate that the S1AI trajectory offers comparable screw length and diameter to an S2AI screw with less implant prominence. An S1AI screw, however, may not be feasible in some patients due to interference from the posterior elements of the lumbar spine.

S2 alar-iliac screws are superior to traditional iliac screws for spinopelvic fixation in adult spinal deformity: a systematic review and meta-analysis

PURPOSE

Spinopelvic fixation (SPF) using traditional iliac screws has provided biomechanical advantages compared to previous constructs, but common complications include screw prominence and wound complications. The newer S2 alar-iliac (S2AI) screw may provide a lower profile option with lower rates of complications and revisions for adult spinal deformity (ASD). The purpose of this study was to compare rates of complications and revision following SPF between S2AI and traditional iliac screws in patients with ASD.

METHODS

A PRISMA-compliant systematic literature review was conducted using Cochrane, Embase, and PubMed. Included studies reported primary data on adult patients undergoing S2AI screw fixation or traditional IS fixation for ASD. Primary outcomes of interest were rates of revision and complications, which included screw failure (fracture and loosening), symptomatic screw prominence, wound complications (dehiscence and infection), and L5-S1 pseudarthrosis.

RESULTS

Fifteen retrospective studies with a total of 1502 patients (iliac screws: 889 [59.2%]; S2AI screws: 613 [40.8%]) were included. Pooled analysis indicated that iliac screws had significantly higher odds of revision (17.1% vs 9.1%, OR = 2.45 [1.25-4.77]), symptomatic screw prominence (9.9% vs 2.2%, OR = 6.26 [2.75-14.27]), and wound complications (20.1% vs 4.4%, OR = 5.94 [1.55-22.79]). S2AI screws also led to a larger preoperative to postoperative decrease in pain (SMD = - 0.26, 95% CI = -0.50, - 0.011).

CONCLUSION

The findings from this review demonstrate higher rates of revision, symptomatic screw prominence, and wound complications with traditional iliac screws. Current data supports the use of S2AI screws specifically for ASD.

PROSPERO ID

CRD42022336515.

LEVEL OF EVIDENCE

III.

Sacropelvic Fixation for Adult Deformity Surgery Comparing Iliac Screw and Sacral 2 Alar-Iliac Screw Fixation: Systematic Review and Updated Meta-Analysis

OBJECTIVE

Two commonly used techniques for spinopelvic fixation in adult deformity surgery are iliac screw (IS) and sacral 2 alar-iliac screw (S2AI) fixations. In this article, we systematically meta-analyzed the complications of sacropelvic fixation for adult deformity surgery comparing IS and S2AI.

METHODS

The PubMed, Embase, Web of Science, and Cochrane clinical trial databases were systematically searched until March 29, 2023. The proportion of postoperative complications, including implant failure, revision, screw prominence, and wound complications after sacropelvic fixation, were pooled with a random-effects model. Subgroup analyses for the method of sacropelvic fixation were conducted.

RESULTS

Ten studies with a total of 1,931 patients (IS, 925 patients; S2AI, 1,006 patients) were included. The pooled proportion of implant failure was not statistically different between the IS and S2AI groups (21.9% and 18.9%, respectively) (p = 0.59). However, revision was higher in the IS group (21.0%) than that in the S2AI group (8.5%) (p = 0.02). Additionally, screw prominence was higher in the IS group (9.6%) than that in the S2AI group (0.0%) (p < 0.01), and wound complication was also higher in the IS group (31.7%) than that in the S2AI group (3.9%) (p < 0.01).

CONCLUSION

IS and S2AI fixations showed that both techniques had similar outcomes in terms of implant failure. However, S2AI was revealed to have better outcomes than IS in terms of revision, screw prominence, and wound complications.

Proximal junctional fractures after long-segment instrumented fusion: comparisons between upper instrumented vertebrae and upper instrumented vertebrae + 1

Introduction

Proximal junctional failure (PJF) is a well-known complication after long-segment (at least 4 vertebral levels) instrumented fusion. The etiologies of PJF include degenerative processes or are fracture induced. The fracture type of PJF includes vertebral fractures developed at the upper instrumented vertebrae (UIV) or UIV + 1. The purpose of this study was to investigate clinical and radiographic features of these two subtypes of PJF and to analyze risk factors in these patients.

Method

In total, forty-two patients with PJF who underwent revision surgery were included. Twenty patients suffered fractures at the UIV, and the other 22 cases had fractures at UIV + 1. The weighted Charlson Comorbidity Index (CCI) and bone mineral density (BMD) T scores for these patients were recorded. Surgery-related data of index surgery and complications were collected. Radiographic parameters including pelvic tilt (PT), pelvic incidence (PI), sagittal vertical axis (SVA), lumbar lordosis (LL), and PI-LL were recorded in both groups before and after the revision surgery.

Result

Both groups had severe osteoporosis and comorbidities. The interval between the index surgery and revision surgery was shorter in the UIV group than in the UIV + 1 group (8.2 months vs. 35.9 months; p < 0.001). The analysis for radiographic parameters in UIV and UIV + 1 group demonstrated no significant change before and after the revision surgery. However, the preoperative radiographic analysis showed a larger PT (31.5° vs. 23.2°, p = 0.013), PI (53.7° vs. 45.3°, p = 0.035), and SVA (78.6° vs. 59.4°, p = 0.024) in the UIV group compared to the UIV + 1 group. The postoperative radiographic analysis showed a larger PI-LL (27.8° vs. 18.1°, p = 0.016) in the UIV group compared to the UIV + 1 group.

Conclusion

PJF in the UIV group tends to occur earlier than in the UIV + 1 group. Moreover, more severe global sagittal imbalances were found in the UIV group than in UIV + 1 group.

The Incidence of Iliac Screw-Related Complications After Long Fusion Surgery in Patients with Adult Spinal Deformity

STUDY DESIGN

Retrospective study.

OBJECTIVE

To investigate the long-term clinical outcome and incidence of iliac screw-related complications in patients with adult spinal deformity (ASD).

SUMMARY OF BACKGROUND DATA

Rigid lumbosacral fixation is crucial to achieve optimal global alignment and successful long-term clinical outcomes.

METHODS

The data of eligible patients with ASD who underwent spinopelvic fixation using bilateral iliac screws with at least 5-year follow-up periods were retrospectively analyzed. Iliac screw loosening and rod breakage between the S1 and iliac (S1/IL) screws were defined as distal instability (DI). Demographic data, health-related quality of life scores, and spinopelvic parameters in the DI group were compared with those in the non-DI group. Sub-group analyses were performed between the cases with and without alignment change after rod fracture at S1/IL.

RESULTS

Of the 159 patients, the data of 110 patients (15 men, 95 women; mean age, 67.8 yr) were analyzed. The follow-up rate was 69%. Forty-five (41%) patients showed DI (29 cases [26%] in screw loosening, 16 cases [15%] in rod breakage). Eight patients (7.3%) required revision surgery because of iliac screw-related complications. No significant differences were observed in the Oswestry Disability Index and Scoliosis Research Society questionnaire (revised) scores between the DI and non-DI groups. The patients with iliac screw loosening showed significantly greater values of preoperative pelvic incidence, pelvic tilt (PT), and postoperative PT, and T1-pelvic angle. In patients with rod breakage at S1/IL, five patients (31%) who had associated mechanical complications showed an alignment change between pre and post rod breakage. They showed significantly higher and lower rates of high-grade osteotomies and L5/S interbody fusion, respectively.

CONCLUSION

The incidence rate of iliac screw-related complications was relatively high. However, they had a little effect on sagittal alignment deterioration and there were few cases that required revision surgery.Level of Evidence: 4.

Does Interbody Support at L5-S1 Matter in Long Fusions to the Pelvis?: A 5-year Analysis

STUDY DESIGN

Retrospective review of prospectively collected data.

OBJECTIVE

To determine if the addition of L5-S1 interbody support in long fusion deformity constructs is associated with superior long-term clinical and radiographic outcomes. To compare the 5-year clinical and radiographic outcomes and complications between long fusion constructs with L5-S1 interbody support versus posterolateral fusion (PLF) alone.

SUMMARY OF BACKGROUND DATA

Cadaveric biomechanical studies have suggested that an interbody fusion at L5-S1 is beneficial in long fusion constructs with sacropelvic fixation. However, there is limited data reflecting the superiority of interbody support augmentation in optimizing arthrodesis and deformity correction relative to PLF alone.

METHODS

Eighty-eight consecutive adults with spinal deformity who underwent at minimum T11-pelvis posterior pedicle screw instrumentation with 5-year follow-up were included. Two cohorts were compared based on technique used at the lumbosacral junction (L5-S1): (A) no interbody (PLF; n = 23), or (B) interbody support at L5-S1 (IB; n = 65). Radiographic measurements and clinical outcome measures were compared at multiple time points. Complications were recorded and compared.

RESULTS

No differences in baseline patient characteristics between cohorts. One nonunion occurred at L5-S1 in the PLF group (P = 0.091). Initial postop sagittal alignment was better in the IB group (PLF: 6.46 cm, IB: 2.48 cm, P = 0.007); however, this was not maintained over long-term follow-up. No significant differences in proximal junctional kyphosis (PLF: 7/23, IB: 9/65, P = 0.076). Proximal junctional failure was more frequent in the PLF group (PLF: 6/23, IB: 6/65, P = 0.043). No significant differences in complications were found. Both cohorts had improvement from baseline pain and functional scores.

CONCLUSION

There is no absolute long-term advantage for lumbar interbody support in adult spinal deformity patients undergoing spinal arthrodesis to the pelvis.Level of Evidence: 3.

Blunt End Wire and Lateral Sacral View: A Technical Trick to Precisely Terminate Percutaneous Pelvic Brim Screw Fixation in the Posterior Ilium

Percutaneous screw fixation in the treatment of a variety of pelvic fractures may involve placement of a pelvic brim or "LC-2" screw. The technique requires the use of the combined obturator oblique inlet view to define the medial and lateral cortical borders of the corridor and an iliac oblique view to define the cranial aspect of the sciatic notch. No technique has been reported on how to safely avoid placement of such percutaneous fixation beyond the posterior cortex of the ilium. A simple technique using the blunt end of a guidewire and a true lateral of the posterior ilium is reported.

Can L5 Be Trusted During Proximal Extension of Fusion? A Case Series and a Review of the Literature

Background

Debate on whether to stop fusion at L5 or to extend fusion to S1 in a long spinal construct has been a controversial topic in spine surgery. Fewer data are available to support whether to include a prior solid fusion at L4-L5 or to extend to S1 during a proximal extension of fusion to T10. The purpose of this review is to report and discuss 2 cases of L5 vertebra fracture after proximal extension of solid L4-L5 fusion to T10 and to provide a guideline to surgeons based on the available literature.

Methods

Case report and literature review.

Results

Literature review identified multiple publications with levels of evidence from level 2 to level 4. Advanced L5-S1 degeneration with long-segment fusion to L5 is reported to be greater than 60% with a new rate of symptom development approaching 20%-25%. There is no prior literature specific to L5 fracture development after thoracic lumbar fusion with the lowest instrumented level at a fused L4-L5 segment. Reoperation rate is not consistently affected by the lowest instrumented vertebral level L5 versus sacrum/ilium.

Conclusions

Literature review is inconclusive as to the need to include the lumbosacral junction when performing a proximal extension of fusion from L5 to the thoracic spine, especially during a revision adult deformity surgery. Stress of the long lever arm of a long-segment thoracolumbar fusion above a prior solid L4-L5 fusion could cause the L5 vertebra to split in the coronal plane, resulting in vertebral body fracture even with a mildly degenerated disc at L5-S1 prior to surgery.

Level of Evidence

4.

Three-level lumbar Ponte osteotomies with less invasive pelvic fixation improve spinal balance, quality of life and decrease disability in adult and elderly women with moderate adult spinal deformity

PURPOSE

To report on quality of life and radiological changes of Ponte osteotomies (POs) with long fixation for primary and revision surgery, in elderly women with adult spinal deformity (ASD).

METHODS

Sixty-seven (67) women, aged 69 ± 7 years, received 3 POs, spinopelvic fixation plus TLIFs. Forty-nine (73%) patients received primary and 18 (27%) revision surgery. Survivorship analysis was made for unplanned revision surgery for broken rods (BR); proximal junction failure (PJF); and deep wound infection (DWI). ODI and SF-36 were used for disability (ODI) and quality of life (SF-36) evaluation.

RESULTS

In total, 201 lumbar POs were made and 9.55 ± 3 levels fused. All patients were available 49 ± 11 months postoperatively. Postoperatively, SVA, CSVL, PI-LL, scoliosis, PT and T9-spinopelvic inclination were reduced, while LL and SS were increased significantly. At the final visit, PI-LL ≤ 10° was achieved in 26 (39.4%) patients; ≤ 15° in 51 (76%) patients, while all 67 patients showed a PI-LL ≤ 20°. Unplanned reoperation was performed in 11 (16.4%) patients: for BR in 5 (7.5%); for PJF in 3 (4.5%) and for DWI in 3 (4.5%) patients, respectively. With end point the reoperation for any reason the survival ± SE was 67.8% ± 0.1; for PJF 89.6 ± 0.065; and for BR 76% ± 0.1 in the final evaluation. There was no difference in survival between the primary and revision surgery groups (P = 0.568). ODI and SF-36 scores were improved postoperatively.

CONCLUSIONS

Three-segment lumbar POs offered and maintained sufficient improvement of lumbar lordosis along with restoration of the sagittal and coronal spinal alignment, improvement of quality of life and disability of female adult and elderly population after primary and revision surgery for ASD.

Accuracy Analysis of Iliac Screw Using Freehand Technique in Spinal Surgery : Relation between Screw Breach and Revision Surgery

Objective

To analyze the accuracy of iliac screws using freehand technique performed by the same surgeon. We also analyzed how the breach of iliac screws was related to the clinical symptoms resulting in revision surgery.

Methods

From January 2009 to November 2015, 100 patients (193 iliac screws) were analyzed using postoperative computed tomography scans. The breaches were classified based on the superior, inferior, lateral, and medial iliac wall violation by the screw. According to the length of screw extrusion, the classification grades were as follows : grade 1, screw extrusion <1 cm; grade II, 1 cm ≤ screw extrusion <2 cm; grade III, 2 cm ≤ screw extrusion <3 cm; and grade IV, 3 cm ≤ screw extrusion. We also reviewed the revision surgery associated with iliac screw misplacement.

Results

Of the 193 inserted screws, 169 were correctly located and 24 were misplaced screws. There were eight grade I, six grade II, six grade III, and four grade IV screw breaches, and 11, 8, 2, and 3 screws violated the medial, lateral, superior, and inferior walls, respectively. Four revision surgeries were performed for the grade III or IV iliac screw breaches in the lateral or inferior direction with respect to its related symptoms.

Conclusion

In iliac screw placement, 12.4% breaches developed. Although most breaches were not problematic, symptomatic violations (2.1%) could result in revision surgery. Notably, the surgeon should keep in mind that lateral or inferior wall breaches longer than 2 cm can be risky and should be avoided.

Safety Profile of Lumbosacropelvic Fixation in Patients Aged 60 Years or Older: Comparison Between S2-Alar-Iliac Screws and Conventional Iliac Screws

STUDY DESIGN

This is a retrospective study.

OBJECTIVE

To report the safety profile of S2-alar-iliac (S2AI) in patients over 60, comparing S2AI screws with iliac screws (ISs).

SUMMARY OF BACKGROUND DATA

The surgical management involving the lumbosacropelvic spine remains a challenge due to high mechanical demand and risk of pseudarthrosis. Previous articles showed lower rates of complications in patients receiving S2AI screws than ISs; however, none of them have focused on patients aged over 60 who may harbor significant comorbidities and thus require more meticulous perioperative management, given these invasive and lengthy procedures.

MATERIALS AND METHODS

Retrospective review of clinical records from 2010 to 2015 identified 60 patients undergoing lumbosacropelvic fixation (17 patients with ISs and 43 patients with S2AI screws) who satisfied the following criteria: (1) patients aged over 60 years old and (2) patients with >1-year follow-up periods. Rates of complications such as unplanned reoperation and cardiorespiratory complications were collected and statistically analyzed.

RESULTS

Baseline characteristics such as age, sex, and comorbidities were similar in both groups. The S2AI group had lower rates of reoperation (18.6% vs. 47.4%; P=0.02), surgical site infection (2.3% vs. 29.4%; P=0.006), wound dehiscence (2.3% vs. 29.4%; P=0.006), and postoperative anemia (7.0% vs. 29.4%; P=0.03) and had lower total volume of estimated blood loss (EBL) (mL) (1846.4 vs. 2721.2; P=0.02) and transfused red blood cell units (7.2 vs. 4.7; P=0.04) than the IS group, while rates of L5-S1 pseudarthrosis and other cardiorespiratory complications were similar in both groups. In multivariate analysis, operative time, body mass index, and use of S2AI screws over ISs were independent predictors of EBL.

CONCLUSIONS

Use of S2AI screws over ISs in patients aged over 60 was associated with lower rates of reoperation, surgical site infection, wound dehiscence, and lower volume of EBL and red blood cell transfusion and is a viable surgical option.

Iliac screws may not be necessary in long-segment constructs with L5-S1 anterior lumbar interbody fusion: cadaveric study of stability and instrumentation strain

BACKGROUND CONTEXT

Lumbosacral pseudoarthrosis and instrumentation failure is common with long-segment constructs. Optimizing lumbosacral construct biomechanics may help to reduce failure rates. The influence of iliac screws and interbody type on range of motion (ROM), rod strain (RS), sacral screw strain (SS) is not well-established.

PURPOSE

Investigate the effects of transforaminal lumbar interbody fusion (TLIF), anterior lumbar interbody fusion (ALIF), and iliac screws on long-segment lumbosacral construct biomechanics.

STUDY DESIGN

Biomechanical study.

PATIENT SAMPLE

Fourteen human cadaveric spine specimens.

OUTCOME MEASURES

Lumbosacral ROM, RS, and SS.

METHODS

Specimens were potted at L1 and the ilium. Specimens were equally divided into either an L5-S1 ALIF or TLIF group and underwent testing in the following conditions: (1) intact (2) L2-S1 pedicle screw rod fixation (PSR-S) (3) L2-ilium (PSR-I) (4) PSR-S+ALIF (ALIF-S) or TLIF (TLIF-S) (5) PSR-I + ALIF (ALIF-I) or TLIF (TLIF-I). Pure moment bending (7.5 Nm) in flexion, extension, lateral bending, axial rotation, and compressive loads (400N) were applied and ROM, SS, and RS were measured. Comparisons were performed using a one-way ANOVA (p<.05).

RESULTS

ALIF-S and TLIF-S provided similar decreases in ROM as TLIF-I (p>.05). Compared to PSR-S, PSR-I significantly decreased SS during bending in all directions (p<.02) but increased RS in flexion and extension (p≤.02). Anterior lumbar interbody fusion-S provided similar decreases in SS as TLIF-I in all directions (p>.40) but had significantly less RS than TLIF-I in flexion, extension, compression (p<.01). TLIF-S had more SS than TLIF-I in flexion, extension, axial rotation (p<.02), while TLIF-S had less RS only in flexion (p=.03). Compared to PSR-I, ALIF-I decreased the RS (p<.02) but TLIF-I did not (p>.67).

CONCLUSIONS

Iliac screws were protective of SS but increased RS at the lumbosacral junction. Constructs with ALIF and no iliac screws result in comparable SS as constructs with TLIF and iliac screws with significantly reduced RS. If iliac screws are utilized, ALIF but not TLIF reduces the iliac screw-induced RS.

CLINICAL SIGNIFICANCE

There is a relatively high incidence of lumbosacral instrumentation failure in adult spinal deformity. Optimizing lumbosacral construct biomechanics may help to reduce failure rates. Iliac screws induce lumbosacral rod strain and may be responsible for instrumentation failure. Constructs with lumbosacral ALIF reduce iliac-screw induced rod strain and may obviate the need for fixation to the ilium.

Low rates of complications after spinopelvic fixation with iliac screws in 260 adult patients with a minimum 2-year follow-up

OBJECTIVE

Recent literature describing complications associated with spinopelvic fixation with iliac screws in adult patients has been limited but has suggested high complication rates. The authors' objective was to report their experience with iliac screw fixation in a large series of patients with a 2-year minimum follow-up.

METHODS

Of 327 adult patients undergoing spinopelvic fixation with iliac screws at the authors' institution between 2010 and 2015, 260 met the study inclusion criteria (age ≥ 18 years, first-time iliac screw placement, and 2-year minimum follow-up). Patients with active spinal infection were excluded. All iliac screws were placed via a posterior midline approach using fluoroscopic guidance. Iliac screw heads were deeply recessed into the posterior superior iliac spine. Clinical and radiographic data were obtained and analyzed.

RESULTS

Twenty patients (7.7%) had iliac screw-related complication, which included fracture (12, 4.6%) and/or screw loosening (9, 3.5%). No patients had iliac screw head prominence that required revision surgery or resulted in pain, wound dehiscence, or poor cosmesis. Eleven patients (4.2%) had rod or connector fracture below S1. Overall, 23 patients (8.8%) had L5-S1 pseudarthrosis. Four patients (1.5%) had fracture of the S1 screw. Seven patients (2.7%) had wound dehiscence (unrelated to the iliac screw head) or infection. The rate of reoperation (excluding proximal junctional kyphosis) was 17.7%. On univariate analysis, an iliac screw-related complication rate was significantly associated with revision fusion (70.0% vs 41.2%, p = 0.013), a greater number of instrumented vertebrae (mean 12.6 vs 10.3, p = 0.014), and greater postoperative pelvic tilt (mean 27.7° vs 23.2°, p = 0.04). Lumbosacral junction-related complications were associated with a greater mean number of instrumented vertebrae (12.6 vs 10.3, p = 0.014). Reoperation was associated with a younger mean age at surgery (61.8 vs 65.8 years, p = 0.014), a greater mean number of instrumented vertebrae (12.2 vs 10.2, p = 0.001), and longer clinical and radiological mean follow-up duration (55.8 vs 44.5 months, p < 0.001; 55.8 vs 44.6 months, p < 0.001, respectively). On multivariate analysis, reoperation was associated with longer clinical follow-up (p < 0.001).

CONCLUSIONS

Previous studies on iliac screw fixation have reported very high rates of complications and reoperation (as high as 53.6%). In this large, single-center series of adult patients, iliac screws were an effective method of spinopelvic fixation that had high rates of lumbosacral fusion and far lower complication rates than previously reported. Collectively, these findings argue that iliac screw fixation should remain a favored technique for spinopelvic fixation.

Second Sacral Alar Screw Fixation: Anatomic Study of Three-Dimensional Computed Tomography and Case Report

OBJECTIVE

S2 alar screw would be an alternative choice without breaking the sacroiliac joint. The aim of this study was to measure radiographic parameters for optimal placement of posterior S2 alar screw for instrumentation and fusion.

METHODS

Three-dimensional computed tomography scans of the pelvis of 60 normal adults were used to map the S2 alar screw. Entry point was typically chosen lateral and superior to the S2 dorsal foramen. Ideal S2 alar screw trajectories were explored by rotating the three-dimensional pelvis, while ensuring trajectories were of maximum length and width. After identification of an optimal trajectory, related linear anatomic parameters and sagittal and transverse angles were determined.

RESULTS

Ideal S2 alar screw trajectories were identified in each computed tomography scan. According to this morphometric study, trajectories for female patients were more lateral in the transverse plane (female 33.73 ± 5.99° vs. male 29.82 ± 4.11°, P < 0.001). Maximal length of trajectory in male patients was significantly longer than in female patients (female 40.82 ± 4.29 mm vs. male 43.42 ± 4.02 mm, P = 0.001). Fourteen S2 alar screws were used in 7 patients with high-grade spondylolisthesis, scoliosis, or nonunion at lumbosacral site. No complications occurred during S2 alar screw placement. One S2 screw failed owing to severe local osteoporosis. No patient developed local pain or wound-related problems.

CONCLUSIONS

S2 alar screw is an alternative sacral fixation point to provide additional biomechanical stability of lumbosacral constructs. A trajectory with maximum length through the S2 ala can be determined using three-dimensional computed tomography.

EVALUATION OF THE RESULTS OF PELVIC FIXATION IN LONG LUMBOSACRAL INSTRUMENTATIONS IN ELDERLY PATIENTS

ABSTRACT Objective: Evaluate the initial results and the possible complications of the combination of pelvic fixation using iliac screws in long instrumentations of the lumbar spine in elderly patients. Methods: An analysis of 38 patients who underwent lumbar spine arthrodesis instrumentation with more than 3 levels, in which we included level L5-S1 and extended the fixation to the iliac crest. Radiological assessment of instrumentation through X-ray of the lumbar spine and pelvis, and computed tomography, to investigate the presence of radiological fusion. Clinical evaluation through a questionnaire of buttock pain including the visual analogue pain score (VAS). Complications related to pelvic instrumentation were investigated. Results: All patients had radiological fusion in the lumbosacral transition. A halo was found around the iliac screw on imaging studies in 31% of patients, but without related symptoms. The questionnaire of buttock pain found that 15% of patients had some low intensity buttock pain (VAS 1-2) and no need to or interest in removing the screws. There was infection at the surgical site in 2% of cases, hematoma in the buttocks in 5%, and vertebral body fracture in the cranial level instrumented in 7% of cases. Conclusions: Pelvic fixation through the iliac screws proved to be effective in protecting the S1 screws in long instrumentations including the L5-S1 level in elderly patients, allowing the radiological bone fusion. The overall results for pain were satisfactory, based on a questionnaire of buttock pain. There are no signs of overload or degeneration of the sacroiliac joints in the early years after surgery. Level of Evidence IV; Case series - therapeutic study.

Spinopelvic Fixation

Fixation at the lumbosacral junction continues to be a challenge for spine surgeons despite advances in spinal instrumentation techniques. The poor bone quality of the sacrum, the complex regional anatomy, and the tremendous biomechanical forces at the lumbosacral junction contribute to the high rates of instrumentation-related complications. Although many spinopelvic fixation techniques have been reported, only a few are still widely used because of the high complication rates associated with previous techniques. Spinopelvic fixation has numerous indications. Long-segment lumbar and thoracolumbar fusions to the sacrum are the most common scenarios in which instrumentation is extended to the pelvis. Surgeons performing complex spinal reconstruction should be familiar with the available techniques, including their potential risks and complications.

Subcrestal Iliac-Screw: A Technical Note Describing a Free Hand, In-line, Low Profile Iliac Screw Insertion Technique to Avoid Side-connector Use and Reduce Implant Complications

STUDY DESIGN

Case-series.

OBJECTIVE

To report our modified iliac-screw insertion technique and its clinical outcomes.

SUMMARY OF BACKGROUND DATA

Iliac-screws are one of the preferred methods for modern spinopelvic-fixation. However, the technique is not without complications, predominantly because of iliac-screw head prominence, leading to pain and revisions. Conventional iliac-screw entry point is sited superficially at the posterior-superior-iliac-spine (PSIS) contributing to screw-head prominence. We propose a more low-profile, subcrestal entry point that is more medial and inferior to the PSIS at the medial wall of the iliac crest, lying underneath the crest but above the sacroiliac joint. This position keeps the screw-head low profile and in-line with proximal instrumentation to ease rod engagement.

METHODS

Ten consecutive patients who underwent spinal deformity correction surgery using the modified iliac-screw entry point fixations were enrolled. Clinical, radiological, and surgical parameters were reviewed.

RESULTS

Five males and five females with average age of 66 years and average follow up of 29 months were reviewed. Mean preoperative Cobb angle and C7-SVA were 32.1° and 10.3 cm, respectively. Surgical indication was progressive deformity and neurogenic claudication in eight cases and fracture in two cases. Twenty noncannulated, polyaxial iliac-screws with median dimension of 7.5 x 75 mm were inserted free hand. Bilateral S1 screws were used in all except two cases. Only five out of 16 iliac-screws with concomitant S1 screws needed side-connectors. At the last follow up only one iliac-screw head was felt to be prominent but without pain in a Parkinson's patient. None of the 10 patients had cases of revision, breakages, or sacroiliac pain.

CONCLUSION

Subcrestal iliac-screw insertion is feasible, safe, and has the potential to reduce screw-head complications and avoid the use of side-connectors, lowering construct complexity and cost. The technique has the advantage of both the low-profile S2 alar iliac screw and the ease of free-hand insertion of the traditional iliac-screw.

LEVEL OF EVIDENCE

4.

S2 Alar Iliac Fixation in Long Segment Constructs, a Two- to Five-Year Follow-up

STUDY DESIGN

Retrospective review of patients having undergone S2 alar-iliac (S2AI) fixation for long fusions with a minimum two-year follow-up.

OBJECTIVES

To report on fusion rates, complications, technique-specific complications of patients having undergone S2AI fixation.

SUMMARY OF BACKGROUND DATA

Sacropelvic fixation continues to be a challenge when performing long fusions to the pelvis. S2AI screws have been found to provide solid biomechanical fixation and have been found to have good clinical results in short-term follow-up for pediatric and adult patients.

METHODS

Cases were retrospectively reviewed in patients who had placement of S2AI screws for long fusions with at least a two-year follow-up. Demographic data, complications, and reoperations were reviewed. Complications were broken into minor and major categories similar to previous series on pelvic fixation.

RESULTS

There were 86 cases identified. Minor and major complications occurred in 29% and 24% of patients, respectively, with the majority of minor complications being intraoperative dural tears. Revision surgery for all causes was performed in 23% of the cohort. Fusion rate at L5-S1 for patients without preoperative pseudarthrosis was 95.3%. Preoperative L5-S1 pseudoarthrosis was identified in 20 patients, 17 (95%) of these went onto fusion after one surgery. There was evidence of S2AI screw lucency in 10.4% of cases. However, the majority of these were asymptomatic.

CONCLUSIONS

Sacropelvic fixation using the S2AI technique provides safe, durable fixation with low rates of technique-specific complications and limited need for hardware removal. Complication rates in this series were similar to other series on long fusions to the pelvis. Additionally, fusion rates were high at L5-S1 for both patients with and without preoperative L5-S1 pseudarthrosis. It appears that the S2AI technique is a powerful option for patients with previous L5-S1 pseudarthrosis.

LEVEL OF EVIDENCE

Level III.

Prevalence and Risk Factors of Iliac Screw Loosening After Adult Spinal Deformity Surgery

STUDY DESIGN

A retrospective study.

OBJECTIVE

We investigated the prevalence of iliac screw loosening and determined risk factors after adult spinal deformity surgery.

SUMMARY OF BACKGROUND DATA

Lumbosacral fixation is crucial to maintain optimal sagittal alignment. Iliac screws are commonly placed to provide protection for sacral pedicle screws. Radiolucent areas around the screws indicate fixation loss and pseudarthrosis.

METHODS

Seventy-two patients with adult spinal deformity (13 men, 59 women; mean age, 69.0 yr) who underwent spinal deformity surgeries using bilateral iliac screws with at least 2 years follow-up were studied. Iliac and S1 screw loosening were assessed by postoperative radiograph. The period of loosening appearance and the relations between loosening and the following items were investigated: (1) upper instrumented vertebra, (2) L5/S interbody fusion, (3) iliac screw placement, (4) spinopelvic parameters (T1 pelvic angle, sagittal vertical axis, pelvic tilt, pelvic incidence-lumbar lordosis [LL]). Oswestry Disability Index scores were obtained preoperatively and 2 years postoperatively.

RESULTS

Iliac and S1 screw loosening was found in 20 (27.8%) and 7 patients (9.7%), respectively. Iliac screw loosening appeared at 5.2 months (range, 3-12) on average. Compared with nonloosening, loosening had significantly higher upper thoracic fusion rates (above T6), lower L5/S interbody fusion rate, higher misplacement rate, and higher insufficient correction rate (PI-LL >10°). Oswestry Disability Index significantly improved in nonloosening, whereas no significant difference was observed in loosening. Multiple regression analysis showed that misplacement (odds ratio = 10.8) and insufficient correction (odds ratio = 7.5) affected loosening.

CONCLUSION

Iliac screw loosening indicated instability of the lumbosacral junction, resulting in sagittal malalignment and poor outcomes. Accurate screw insertion and restoration of optimal LL were necessary to prevent complications.

LEVEL OF EVIDENCE

4.

Accuracy of Iliac Screws Insertion in Adult Spinal Deformity Surgery: Relationship Between Misplacement and the Iliac Morphologies

STUDY DESIGN

Retrospective study.

OBJECTIVE

To investigate the accuracy of freehand iliac screw insertion and to determine how this can be performed safely.

BACKGROUND AND METHODS

Seventy-seven adult scoliosis patients with an average age of 70.1 years who underwent spinal deformity surgery with spinopelvic fixation using bilateral iliac screws were enrolled. Penetration of the iliac table was assessed using postoperative computed tomography. Screw penetration of the iliac table or screw insertion from the sacroiliac joint was considered misplacement. Screw positioning was classified as the screw being in the proper position (group C), the screw penetrating the outer table (group O), and the screw penetrating the inner table (group I). The iliac opening angle and the distance between the posterior superior iliac spines (PSISs) were measured using preoperative computed tomography. The angle between the sacral slope and the iliac screw, termed as the sagittal screw angle, was measured using postoperative lateral lumbar radiography.

RESULTS

Of the 154 iliac screws in 77 patients, 14 screws in 12 patients penetrated the outer table and 12 screws in 11 patients penetrated the inner table. The total proportion of misplacement was 18.8%, although there were no major complications. With regard to iliac morphology, the iliac opening angle was 24.2±4.3 degrees and the distance between the PSISs was 90.6±7.7 mm. The distance between the PSISs correlated negatively with the iliac opening angle. The iliac opening angle was smaller in group O than in group C (P<0.05). The sagittal screw angle in group I was smaller than that in group C (P<0.01).

CONCLUSIONS

Screw penetration of the outer iliac table possibly occurred in patients with a narrow iliac opening angle. Screw penetration of the inner table occurred when the screw was inserted more cranially than the sacral slope. Therefore, the iliac screw should be inserted approximately parallel to the sacral slope.

Is pelvic fixation the only option to provide additional stability to the sacral anchorage in long lumbar instrumentation? A comparative biomechanical study of new techniques

BACKGROUND

Supplementary iliac screws have the highest potential to protect S1-pedicle-screws from loosening in long fusion constructs. However, this technique bridges the iliosacral joint with potential disadvantages for the patient. This study aimed to evaluate if two different established fixation techniques can be used in addition to pedicle screws as alternative to iliac screws, and if these two techniques can provide similar stability when S1-pedicle-screws are loosened.

METHODS

Flexibility testing with pure moments of 7.5Nm was performed with six human osteopenic/osteoporotic L4-pelvis specimens. The following conditions were investigated: 1. Intact; 2. Destabilization L5/S1; 3. Fixation with rigid L4-S1 pedicle-screw-system; 4. Condition 3- loosening of S1-screws; 5. Condition 4- L5-S2-lamina-hooks; 6. Condition 4- L5/S1-translaminar-screws; 7. Condition 4- S2-ala-ilium screws.

FINDINGS

Application of compressive L5-S2-lamina-hooks or L5/S1-translaminar-screws next to pedicle screws in L5 and S1 was feasible in all specimens. L4-S1-pedicle-screw-instrumentation reduced the Range of Motion significantly compared to the destabilized condition. After simulation of S1 screw loosening, lamina hooks only reduced the Range of Motion in flexion/extension significantly. L5/S1-translaminar-screws had a higher stabilizing effect in lateral bending and axial rotation, but the effect of both systems was smaller than with an instrumentation extension to the os ilium.

INTERPRETATION

In long lumbar pedicle screw instrumentations including L5/S1, additional ilium screws have the highest potential to protect the S1-anchorage. Additional L5/S1-translaminar-screws can increase stability of the lumbosacral junction without bridging the iliosacral joint, whereas lamina hooks showed no significant biomechanical benefit.

Use of S2-Alar-iliac Screws Associated With Less Complications Than Iliac Screws in Adult Lumbosacropelvic Fixation

STUDY DESIGN

Retrospective comparative study.

OBJECTIVE

To compare clinical and radiographic outcomes between the S2-alar-iliac (S2AI) and the iliac screw (IS) techniques in the adult population and clarify the clinical strength of S2AI screws.

SUMMARY OF BACKGROUND DATA

S2AI screws have been described as an alternative method for lumbosacropelvic fixation in place of ISs. The S2AI technique has several advantages with lower prominence, increased ability to directly connect to proximal instrumentation, less extensive dissection of tissue, and enhanced biomechanical strength over the IS technique. However, the clinical significance of these advantages remains unclear.

METHODS

A single-center retrospective review of patients who underwent lumbosacropelvic fixation yielded 25 IS group patients and 65 S2AI group patients. Baseline demographic information, postoperative complications, pain and functional outcomes, and screw-related outcomes were collected.

RESULTS

The S2AI group had lower rates of reoperation (8.8% vs. 48.0%, P < 0.001), surgical site infection (SSI) (1.5% vs. 44.0%, P < 0.001), wound dehiscence (1.5% vs. 36.0%, P < 0.001), and symptomatic screw prominence (0.0% vs. 12.0%, P = 0.02) than the IS group, whereas rates of L5-S1 pseudarthrosis, proximal junctional failure, and sacroiliac joint pain were similar in both groups. Statistically significant pain relief and functional recovery were achieved in both groups without any significant intergroup differences. On multivariate analyses, age [odds ratio (OR) = 0.91, P = 0.004] and S2AI instrumentation (OR = 0.08, P < 0.001) were protective of reoperation, whereas diabetes mellitus (OR = 10.9, P = 0.03) and preoperative diagnosis of tumor (OR = 12.3, P = 0.04) were associated with SSI, and S2AI instrumentation (OR = 0.09, P < 0.001) was protective of SSI.

CONCLUSION

The use of the S2AI technique over the IS technique was an independent predictor of preventing reoperation and SSI, while achieving similar clinical and functional outcomes.

LEVEL OF EVIDENCE

4.

Sacral-Alar-Iliac Fixation in Pediatric Deformity: Radiographic Outcomes and Complications

STUDY DESIGN

Retrospective case series.

OBJECTIVES

To assess the radiographic outcomes and complications of sacral-alar-iliac (SAI) fixation in children.

SUMMARY OF BACKGROUND DATA

Pelvic fixation in children undergoing spinal deformity surgery can be challenging because of complex anatomy, compound biomechanical forces at the lumbosacral junction, and poor bone quality.

METHODS

Radiographic and clinical records of 80 consecutive patients aged 18 years or younger who underwent posterior spinal fusion surgery with SAI fixation by one pediatric orthopedic surgeon and who had a minimum 2 years of follow-up (mean follow-up: 3.5 years, range, 2-7 years) were retrospectively reviewed. Changes in coronal curve magnitude and pelvic obliquity were assessed using Student t tests. Significance was set at a p value less than .05 for all analyses.

RESULTS

Pelvic obliquity correction averaged 77%, from 26 ± 13 degrees before surgery to 6 ± 4 degrees at final follow-up (p < .001); 91% of the patients were corrected to a pelvic obliquity of less than 10 degrees. Coronal curve correction averaged 72%, from 78 ± 27 degrees before surgery to 22 ± 15 degrees at final follow-up (p < .001). No patient had vascular or neurologic complications or died perioperatively. Twenty patients (25%) had radiographic evidence of implant-related problems, of which there were nine screw fractures (all in the neck of screws with ≤8-mm outer diameter). Six patients had symptomatic complications associated with SAI fixation (three patients with pseudarthrosis at the lumbosacral junction, all of whom required revision surgery, two patients with implant prominence, and one patient with pain related to implant). Other complications included seven instances of wound dehiscence, three deep wound infections, and one superficial wound infection.

CONCLUSIONS

SAI fixation provided a low-profile alternative to iliac screws for the correction of pelvic obliquity. The largest possible diameter screws are recommended, ideally >8 mm.

LEVEL OF EVIDENCE

Level 4.

Unplanned reoperation after lumbopelvic fixation with S-2 alar-iliac screws or iliac bolts

OBJECT

S-2 alar-iliac (S2AI) screws are an attractive alternative to conventional fixation with iliac bolts because they are lower profile, require less muscle dissection, and have greater pullout strength. Few studies, however, compare outcomes between these techniques.

METHODS

The authors conducted a retrospective cohort study of consecutive adult patients at a single institution from December 2009 to March 2012 who underwent lumbopelvic fixation using S2AI screws or iliac bolts. Medical records were reviewed for patients with clinical failure, defined as an unplanned reoperation because of instrumentation failure and/or wound-related complications. Univariate, multivariate, and survival analyses were used to compare patients who required reoperation with those who did not. Method of pelvic fixation was the main predictor variable of interest, and the authors adjusted for potential confounding risk factors.

RESULTS

Of the 60 patients included, 23 received S2AI screws. Seventeen patients (28%) underwent an osteotomy. The mean follow-up was 22 months. A Kaplan-Meier survival model was used to evaluate the time to reoperation from the initial placement of lumbopelvic instrumentation. The failure-free rate was 96.6% at 6 months, 87.0% at 1 year, and 73.5% at 2 years. Reoperation was more common in patients with iliac bolts than in those with S2AI screws (13 vs 2; p = 0.031). Univariate analysis identified potential risk factors for unplanned reoperation, including use of iliac bolts (p = 0.031), absence of L5–S1 interbody graft (p = 0.048), previous lumbar fusion (p = 0.034), and pathology other than degenerative disease or scoliosis (p = 0.034). After adjusting for other risk factors, multivariate analysis revealed that the use of S2AI screws (OR 8.1 [1.5–73.5]; p = 0.030) was the only independent predictor for preventing unplanned reoperation.

CONCLUSIONS

Both S2AI screws and iliac bolts were effective at improving fusion rates at the lumbosacral junction. The use of S2AI screws, however, was independently associated with fewer unplanned reoperations for wound-related complications and instrumentation failures than the use of iliac bolts.

Entry zone of iliac screw fixation to maintain proper entry width and screw length

PURPOSE

To evaluate the entry zone of iliac screw fixation to maintain proper entry width and screw length.

METHODS

Computed tomography images of pelvic bones from 90 human cadavers were reconstructed into 3-dimensional models. In each model, a sectional image crossing the posterior superior iliac spine (PSIS) and anterior inferior iliac spine (AIIS) and consecutive sectional images up to 20 mm superiorly and inferiorly from the PSIS with 1-mm intervals aiming the AIIS were obtained. One virtual iliac screw with 10-mm diameter was introduced onto the PSIS at the middle and at the lateral and medial 1/4 points on the prominence of the posterior iliac spine. The entry width of the bony prominence and the corresponding maximal screw length available were evaluated for each entry point.

RESULTS

The entry width was smallest on the inferior 20 mm (4.7 ± 3.0 mm) and gradually increased up to the superior 10 mm (19.1 ± 3.9 mm) sectional images. The maximal screw length was smallest on the superior 20 mm (76.7 ± 39.7 mm) and gradually increased down to the inferior 10 mm (112.3 ± 15.1 mm) sectional images. The maximal screw lengths were significantly greatest at the most medial point and smallest at the most lateral point on the superior 20- and 10-mm sectional images and at the PSIS.

CONCLUSIONS

The iliac screw fixation entry zone to maintain proper screw length and entry width is outlined from 20 mm superiorly to 10 mm inferiorly from the PSIS and is located more medially from the prominence of the posterior iliac spine.

Incidence, diagnosis, and management of sacral fractures following multilevel spinal arthrodesis

BACKGROUND

Fractures of the sacrum are a rare complication following instrumented spinal fusion, with only 34 cases previously reported in the literature. Previous series have generally been limited to less than five cases.

PURPOSE

The purpose of this study is to determine the incidence of sacral fractures caudal to instrumented spinal fusion constructs, identify risk factors for fracture and for failure of conservative management, and describe strategies for surgical treatment of these fractures.

STUDY DESIGN

This is a retrospective review.

PATIENT SAMPLE

Patients undergoing instrumented posterior spinal arthrodesis between 2002 and 2011 were included in the sample.

OUTCOME MEASURES

Clinical and radiographic data from hospital and surgeon records comprise outcome measures.

METHODS

Methods include a review of clinical and radiographic data from a prospectively collected patient database recording all adjacent segment fractures during the study period.

RESULTS

Twenty-four patients developed sacral fractures caudal to instrumented spinal fusion constructs during the study period. The overall incidence was 6.1% and was significantly greater in fusions greater than four levels (14.5%). The mean time from index surgery to fracture was 4.3 months. Only one fracture was evident on plain radiography at the onset of symptoms. Computed tomography, magnetic resonance imaging, and nuclear scintigraphy can all be used to establish the diagnosis. Eight patients were successfully treated conservatively. The mean time to fracture union was 21 weeks. Anterolisthesis of the fracture greater than 2 mm and kyphotic angulation were significantly associated with failure of conservative management. Surgical intervention included posterior extension of the fusion construct to S2 and the iliac wings with sacroiliac joint fusion. In 10 cases, a combined anterior and posterior approach was used that consisted of either revision anterior lumbar interbody fusion or transsacral posterior lumbar interbody fusion.

CONCLUSIONS

Sacral fractures following instrumented posterior spinal fusion are an uncommon complication; that is often unrecognized on plain radiographs. Risk factors include osteoporosis and long spinal fusions. Anterolisthesis and kyphosis of the fracture is associated with failure of conservative management.

Surgical treatment of adult degenerative scoliosis

INTRODUCTION

The surgical treatment of adult scoliosis still presents many points of discussion. Decision-making on the type of treatment is mandatory to evaluate all the possible alternatives to surgery.

MATERIALS AND METHODS

From January 2000 to December 2008, 49 cases of adult degenerative scoliosis and kyphoscoliosis were surgically treated. Thirty-six patients were monitored for a mean of 8 years (5-10). There were 10 males and 26 females, with a mean age of 66 years (55-80). Arthrodesis was carried out using pedicle screws at all levels extending to the sacrum in 30 cases and to the ileum in 4. Laminectomy was performed in 20 cases, radicular liberation in 15, PLIF in 10.

RESULTS

After an average term of 8 years (5-10) we record 8 (23 %) excellent cases, 10 (29 %) good, 12 (34 %) satisfactory, 5 (14 %) bad. The VAS in the pre-operative period had a value of 7 (5-9) passed in the post-operative period of 3 (0-6). 13 reoperations were performed (36 %).

Failure of lumbopelvic fixation after long construct fusions in patients with adult spinal deformity: clinical and radiographic risk factors: clinical article

OBJECT

Lumbopelvic fixation provides biomechanical support to the base of the long constructs used for adult spinal deformity. However, the failure rate of the lumbopelvic fixation and its risk factors are not well known. The authors' objective was to report the failure rate and risk factors for lumbopelvic fixation in long instrumented spinal fusion constructs performed for adult spinal deformity.

METHODS

This retrospective review included 190 patients with adult spinal deformity who had long construct instrumentation (> 6 levels) with iliac screws. Patients' clinical and radiographic data were analyzed. The patients were divided into 2 groups: a failure group and a nonfailure group. A minimum 2-year follow-up was required for inclusion in the nonfailure group. In the failure group, all patients were included in the study regardless of whether the failure occurred before or after 2 years. In both groups, the patients who needed a revision for causes other than lumbopelvic fixation (for example, proximal junctional kyphosis) were also excluded. Failures were defined as major and minor. Major failures included rod breakage between L-4 and S-1, failure of S-1 screws (breakage, halo formation, or pullout), and prominent iliac screws requiring removal. Minor failures included rod breakage between S-1 and iliac screws and failure of iliac screws. Minor failures did not require revision surgery. Multiple clinical and radiographic values were compared between major failures and nonfailures.

RESULTS

Of 190 patients, 67 patients met inclusion criteria and were enrolled in the study. The overall failure rate was 34.3%; 8 patients had major failure (11.9%) and 15 had minor failure (22.4%). Major failure occurred at a statistically significant greater rate in patients who had undergone previous lumbar surgery, had greater pelvic incidence, and had poor restoration of lumbar lordosis and/or sagittal balance (that is, undercorrection). Patients with a greater number of comorbidities and preoperative coronal imbalance showed trends toward an increase in major failures, although these trends did not reach statistical significance. Age, sex, body mass index, smoking history, number of fusion segments, fusion grade, and several other radiographic values were not shown to be associated with an increased risk of major failure. Seventy percent of patients in the major failure group had anterior column support (anterior lumbar interbody fusion or transforaminal lumbar interbody fusion) while 80% of the nonfailure group had anterior column support.

CONCLUSIONS

The incidence of overall failure was 34.3%, and the incidence of clinically significant major failure of lumbopelvic fixation after long construct fusion for adult spinal deformity was 11.9%. Risk factors for major failures are a large pelvic incidence, revision surgery, and failure to restore lumbar lordosis and sagittal balance. Surgeons treating adult spinal deformity who use lumbopelvic fixation should pay special attention to restoring optimal sagittal alignment to prevent lumbopelvic fixation failure.

Sexual function in older adults following thoracolumbar to pelvic instrumentation for spinal deformity

Object

Sexual function is an often-overlooked aspect of health-related quality of life among older adults treated for spinal deformity. The authors' objective was to assess sexual function among older adults following thoracolumbar fusion with pelvic fixation for spinal deformity.

Methods

This was a retrospective review of consecutive older adults (≥50 years) treated with posterior thoracolumbar instrumentation (including pelvic fixation) for spinal deformity and with a minimum 18-month follow-up. Patients completed the Changes in Sexual Function Questionnaire-14 (CSFQ-14), Oswestry Disability Index (ODI), and 12-Item Short-Form Health Survey (SF-12).

Results

Sixty-two patients (45 women and 17 men) with a mean age of 70 years (range 50–83 years) met the inclusion criteria. Eight women did not complete all questionnaires and were excluded from the subanalysis. The mean number of instrumented levels was 9.8 (range 6–18), and the mean follow-up was 36 months (range 19–69 months). Based on the CSFQ-14, 13 patients (24%) had normal sexual function, and 8 (15%), 10 (19%), and 23 (42%) had mild, moderate, and severe dysfunction, respectively. Thirty-nine percent of patients reporting severe sexual dysfunction did not have available partners—23% because of a partner's death and 16% because of a partner's illness)—or had significant medical comorbidities of their own (48%). Thirty-nine percent of assessed patients had either no or only mild sexual dysfunction. Patients with minimal or mild disability tended to have no or mild sexual dysfunction.

Conclusions

The authors of this study assessed sexual function in older adults following surgical correction of spinal deformity that included posterior instrumented fusion and iliac bolts. Nearly 40% of assessed patients had either no or only mild sexual dysfunction, suggesting that despite an older age and extensive spinopelvic instrumentation, it remains very possible to maintain or achieve satisfactory sexual function.